Assessing the Efficacy of Three Hatchery Disinfectants for the Inactivation of a Lake Sturgeon Herpesvirus (Family: Alloherpesviridae)

Abstract

Infectious diseases are a leading cause of losses in the aquaculture industry and conservation programs globally. Simultaneously, infectious diseases pose a substantial risk to fish being hatchery-reared and released into natural habitats for conservation purposes, including the Great Lakes lake sturgeon (Acipenser fulvescens, i.e., GL-LST). Recently, an alloherpesvirus (lake sturgeon herpesvirus 2, i.e., LSHV-2) capable of inducing disease and/or mortality in adult and juvenile GL-LSTs was detected in two adult GL-LST populations. To begin developing disease prevention and/or control methods, in vitro experiments were designed to determine the susceptibility of LSHV-2 to disinfectants commonly used in hatchery and aquaculture facilities (Virkon®-Aquatic: potassium peroxymonosulfate; Ovadine®: polyvinylpyrrolidone iodine complex; and Perox-Aid®: hydrogen peroxide). Cultured LSHV-2 was exposed to each disinfectant at two concentrations (Virkon®-Aquatic: 0.5% and 1%; Ovadine®: 50 and 100 ppm; and Perox-Aid®: 500 and 1000 ppm) in duplicate for durations of 1, 10, and 30 min. Following exposure, the disinfectant was neutralized, and after a 14-day incubation period on a white sturgeon × lake sturgeon hybrid cell line (WSxLS), percent reduction was calculated by comparing the 50% tissue culture infectious doses (TCID50/mL) of the virus with and without disinfectant exposure. When exposed to Perox-Aid®, LSHV-2 percent reduction ranged from 58.7% to 99.5%. When exposed to Ovadine®, the percent reduction ranged from 99.4% to 100%. Lastly, the percent reduction when exposed to Virkon®-Aquatic was 100% for both concentrations and all timepoints. The results herein provide evidence that both Virkon®-Aquatic and Ovadine® are virucidal to LSHV-2 and may represent a means to reduce virus transmission risk under field settings.